dubious vs quicksilver

dubious

adj
  • In disbelief; wavering, uncertain, or hesitating in opinion; inclined to doubt; undecided. 

  • Arousing doubt; questionable; open to suspicion. 

  • Generally considered imprecise or wrong, but not totally unplayable. 

quicksilver

adj
  • Unpredictable, erratic or fickle; mercurial. 

verb
  • To overlay with quicksilver. 

  • To treat with quicksilver. 

noun
  • The metal mercury. 

  • An amalgam of mercury and tin applied to the backs of mirrors, quicksilvering. 

How often have the words dubious and quicksilver occurred in a corpus of books? (source: Google Ngram Viewer )